Vaporizer, semiconductor production apparatus  and process of semiconductor production

ABSTRACT

A vaporizer, a semiconductor production apparatus and process capable of improving the efficiency in the use of a raw material gas noticeably, enabling uniform deposition according to the raw material gas used, diminishing maintenance frequency to improve productivity. At the time of ALD operation, carrier gas continues to be supplied to a reaction chamber  402 , while supplying a material solution of predetermined quantity according to a film thickness of one atomic or molecular layer determined by a micro-metering pump  54 , intermittently to an evaporation mechanism  20 . Thus, a gas shower type heat CVD apparatus  1  enables a thin film of a desired thickness made of one atomic or molecular layer to be formed on a substrate  420  one by one, while avoiding the raw material gas being thrown away by the opening or closing operation of the reaction-chamber side valve  404  and the vent side valve  407 . Consequently, the efficiency in the use of the raw material gas can be improved remarkably, according to the quantity of the raw material gas that is not thrown away in the process of forming a thin film of one atomic or molecular layer one by one.

TECHNICAL FIELD

The present invention relates to a vaporizer, a semiconductor productionapparatus and a process of semiconductor production. The presentinvention is preferably applicable to an ALD (Atomic LayerDeposition)-type CVD (Chemical Vapor Deposition) apparatus where amaterial gas is intermittently supplied to a reaction chamber to grow athin film, layer by layer with respect to an atomic or molecular layer.

BACKGROUND ART

Semiconductor integrated circuits are manufactured by numerousrepetitions of the forming and patterning of a thin film. Various kindsof CVD apparatuses are used for forming a thin film. One example of CVDapparatuses having an advantageous uniform deposition property andenabling the formation of a high quality film, is an ALD type CVDapparatus, disclosed in for example Japanese Un-examined PatentPublication No. 2006-28572, in which a raw material gas is sprayed ontoa substrate intermittently, which is then heated by a heating devicesuch as a heater to cause a chemical reaction, to thereby form a thinfilm on the substrate.

For example, a CVD apparatus 400 for use with ALD shown in FIG. 9includes a CVD section 401 of a gas shower type, having a reactionchamber 402 with a gas introduction port 403 in fluid communication witha gas supply passage 405 via a valve 404 at the reaction chamber side.The gas supply passage 405 includes a branch section 406 at an upperstream side of the valve 404, and another valve 407 at a vent side isprovided in this branch section 406.

An exhaust tube 408 is connected to the vent side valve 407, and thusthe gas supply passage 405 is constituted so that it may be able tocommunicate with an exhaust vacuum pump 410 through the vent side valve407, the exhaust tube 408, and the exhaust valve 409.

In the meantime, the reaction chamber 402 comprises a lid section 411which has the gas introduction port 403, a reaction-chamber supportingsection 412 which supports the reaction chamber 402, and areaction-chamber body 413. The internal 415 of the reaction chamber isable to be kept at a predetermined temperature with a heater (not shown)provided in for example an outside face of the reaction chamber body413. A shower plate 416 is provided in the internal 415 of the reactionchamber, said shower plate 416 having an interior space 417 forreceiving a raw material gas from the gas introduction port 403, havingtwo or more gas ejecting holes 418 provided in the undersurface thereof.

With the structure thus made, in the ALD-CVD apparatus 400, the valve404 at the reaction chamber side is turned into an opened state whilethe vent side valve 407 into a closed state when forming a thin film,whereby a raw material gas is supplied to the reaction chamber 402, andthe raw material gas is uniformly sprayed on a substrate 420 through thegas ejecting hole 418. Thus, the raw material gas is heated by theheater 422 or the like in a substrate stage 421 in the internal 415 ofthe reaction chamber, thus allowing a chemical reaction to occur on thesubstrate 420.

Thereafter, in the CVD apparatus 400 for ALD, the reaction-chamber sidevalve 404 is switched into a closed state at a predetermined rightmoment, while the vent side valve 407 into an opened state, therebystopping the supply of a raw material gas to the internal 415 of thereaction chamber, to thereby form a thin film of one atomic layer ormolecular layer of a desired deposition thickness.

Moreover, the CVD apparatus 400 for ALD is constituted such that whenthe forming operation of the thin film of the aforesaid one atomic layeror one molecular layer is finished, another thin film of one atomic ormolecular layer of a desired film thickness is formed on the substrate420, by performing the closing or opening operation (namely, thin-filmformation operation) of the reaction chamber side valve 404 and the ventside valve 407 again after the lapse of predetermined time.

Thus, the CVD apparatuses 400 for ALD is constituted such that a rawmaterial gas is intermittently supplied to the reaction chamber 402 toform a film of a predetermined thickness sequentially by performing theALD operation that repeats the thin-film forming operation two or moretimes so that a high-density and high-quality thin film can be formed onthe substrate 420.

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

According to such CVD apparatus 400 for ALD, however, every time a rawmaterial gas is intermittently supplied to the reaction chamber 402, thereaction-chamber side valve 404 is switched into the closed state, whilethe vent side valve 407 into a closed state so that the raw material gasto be supplied to the reaction chamber 402 is supplied to the exhausttube 408 and disposed as it is. As a result, there has been a problemthat when supplying a raw material gas to the reaction chamber 402intermittently, the efficiency in the use of a raw material gas getsworse by the disposed amount thereof.

Moreover, according to such CVD apparatus 400 for ALD, pressure andtemperature in the reaction chamber interior 415 is liable to be changedeasily every time the opening or closing operation of thereaction-chamber side valve 404 is repeated, so that the depositionprocess conditions in the internal 415 of the reaction chamber becomenon-uniform. As a result, there has been a problem that forming a thinfilm uniformly on the substrate 420 is difficult.

Furthermore, according to such CVD apparatus 400 for ALD, the opening orclosing operation of the reaction-chamber side valve 404 and the ventside valve 407 is performed repeatedly, thus resulting in the increaseof the opening or closing operations thereof, eventually leading to ashort operating life in general. For this reason, maintenance of thereaction-chamber side valve 404 and the vent side valve 407 in a shortperiod has been required. As a result, there has been a problem thatoperating ratio drops, and improvement of productivity is difficult.

The present invention has been made in view of the above problems. Itis, therefore, an object of the present invention to provide avaporizer, method and apparatus for production of a semiconductor, whichenables the forming of a uniform thickness film, noticeably improving ofthe efficiency in the use of the raw material gas, decreasing themaintenance frequency as compared with the conventional art.

Means for Solving the Problems

A vaporizer according to a first aspect of the invention is a vaporizerfor supplying a raw material gas to a reaction chamber, said materialgas being obtained by evaporating a material solution, comprising:

a carrier gas passage for allowing the carrier gas to flow from an inlettoward an outlet;

a material solution passage to which said material solution is supplied;

a connecting pipe for communicating said carrier gas passage with saidmaterial solution passage;

a material solution discharging means for determining quantity of saidmaterial solution supplied to said material passage to discharge thesame to said connecting pipe;

an evaporating section provided between the outlet of said carrier gaspassage and said material solution discharging means, said evaporatingsection evaporating a predetermined quantity of said material solutiondischarged from said material solution discharging means.

According to the vaporizer of a second aspect, said material solutiondischarging means discharges said material solution intermittently tosaid connecting pipe.

The vaporizer of a third aspect further comprises a solvent passage forsupplying a purge solvent to said carrier gas passage.

According to the vaporizer of a fourth aspect of the invention, saidcarrier gas passage comprises:

a carrier gas tube to which said carrier gas is supplied;

an orifice pipe having said carrier gas supplied from said carrier gastube, said orifice pipe turning said material solution into the form offine particles or mists to be supplied to said evaporating section withsaid material solution being dispersed into the carrier gas, and

wherein said evaporating section comprises a heating means for heatingand evaporating said material solution dispersed in said carrier gas.

According to the vaporizer of a fifth aspect of the invention, saidmaterial solution discharging means comprises a micro-metering pump.

According to the vaporizer of a sixth aspect of the invention, saidmaterial solution discharging means determines quantity of said materialsolution supplied to said material solution passage so that thedetermined quantity thereof corresponds to that required for a filmthickness of 500 nm or less to be formed on a substrate.

According to the vaporizer of a seventh aspect of the invention, saiddetermined quantity of the material solution corresponds to thatrequired for forming one atomic layer or one molecular layer formed onsaid substrate.

According to the vaporizer of an eighth aspect of the invention, saidmaterial solution discharging means comprises a storage section forstoring a specific quantity of said material solution, corresponding tothat required for forming one atomic layer or one molecular layer.

According to the vaporizer of a ninth aspect of the invention, saidmaterial solution discharging means stores said specific quantity of thematerial solution supplied from a material solution tank in said storagesection beforehand so that it may be discharged to said evaporatingsection at a predetermined moment.

A semiconductor production apparatus of a tenth aspect of the inventionis the one including a reaction chamber for placing a substrate thereonand a vaporizer for supplying a raw material gas to the reactionchamber, said material gas being obtained by evaporating a materialsolution,

wherein said vaporizer comprises:

a carrier gas passage for allowing the carrier gas to flow from an inlettoward an outlet;

a material solution passage to which said material solution is supplied;

a connecting pipe for communicating said carrier gas passage with saidmaterial solution passage;

a material solution discharging means for determining quantity of saidmaterial solution supplied to said material passage to discharge thesame to said connecting pipe;

an evaporating section provided between the outlet of said carrier gaspassage and said material solution discharging means, said evaporatingsection evaporating a predetermined quantity of said material solutiondischarged from said material solution discharging means.

The semiconductor production apparatus of an eleventh aspect of theinvention is the one wherein said material solution discharging meansdischarges said material solution intermittently to said connectingpipe.

The semiconductor production apparatus of a twelfth aspect of theinvention further comprises a solvent passage for supplying a purgesolvent to said carrier gas passage.

According to the semiconductor production apparatus of a thirteenthaspect of the invention,

said carrier gas passage comprises:

a carrier gas tube to which said carrier gas is supplied;

an orifice pipe having said carrier gas supplied from said carrier gastube, said orifice pipe turning said material solution into the form offine particles or mists to be supplied to said evaporating section withsaid material solution being dispersed into the carrier gas, and

wherein said evaporating section comprises a heating means for heatingand evaporating said material solution dispersed in said carrier gas.

According to the semiconductor production apparatus of a fourteenthaspect of the invention, said material solution discharging meanscomprises a micro-metering pump.

According to the semiconductor production apparatus of a fifteen aspectof the invention, said material solution discharging means determinesquantity of said material solution supplied to said material solutionpassage so that the determined quantity thereof corresponds to thatrequired for a film thickness of 500 nm or less to be formed on asubstrate.

According to the semiconductor production apparatus of a sixteenthaspect of the invention, said determined quantity of the materialsolution corresponds to that required for forming one atomic layer orone molecular layer formed on said substrate.

According to the semiconductor production apparatus of a seventeenthaspect of the invention, said material solution discharging meanscomprises a storage section for storing a specific quantity of saidmaterial solution, corresponding to that required for forming one atomiclayer or one molecular layer.

According to the semiconductor production apparatus of an eighteenthaspect of the invention, said material solution discharging means storessaid specific quantity of the material solution supplied from a materialsolution tank in said storage section beforehand so that it may bedischarged to said evaporating section at a predetermined moment.

A process of producing a semiconductor of a nineteenth aspect of theinvention, is the one in which a raw material gas obtained byevaporating a material solution is supplied into a reaction chamberwhere a substrate is surface treated, said method comprising:

a carrier gas supply step for supplying the carrier gas to said reactionchamber by allowing the carrier gas to flow from an inlet toward anoutlet of a carrier gas passage;

a material-solution supply step for supplying said material solution tosaid material solution passage;

a quantitating step for determining quantity of said material solutionsupplied to said material solution passage;

a material solution discharging step for discharging a predeterminedquantity of said material solution quantitated in the quantitating stepto said connecting pipe communicating said carrier gas passage with saidmaterial solution passage; and

an evaporating step for evaporating said predetermined quantity of saidmaterial solution discharged in said material solution discharging step,using an evaporating section provided between the outlet of said carriergas passage and a means for discharging said material solution.

According to the process of producing a semiconductor of a twentiethaspect of the invention, said material solution is dischargedintermittently to said connecting pipe in said material solutiondischarging step.

The process of producing a semiconductor of a twenty-first aspect of theinvention comprises a purge solvent supply step for supplying a purgesolvent to said evaporating section from said carrier gas passagethrough said connecting pipe, instead of said material solutiondischarging step and said evaporating step.

According to the process of producing a semiconductor of a twenty-secondaspect of the invention, said carrier gas supply step includes asub-step for supplying said carrier gas to said orifice pipe from saidcarrier gas tube; and after the sub-step, said material solution isdischarged to said orifice pipe in said material solution dischargingstep, so that said material solution turned into the form of fineparticles or mists in said orifice pipe to be supplied to saidevaporating section with said material solution being dispersed into thecarrier gas, and then said material solution dispersed in said carriergas through said evaporating step is heated by a heating means providedin said evaporating section.

According to the process of producing a semiconductor of a twenty-thirdaspect of the invention, quantity of said material solution isdetermined by a micro-metering pump in said quantitating step.

According to the process of producing a semiconductor of a twenty-fourthaspect of the invention, in said quantitating step, quantity of saidmaterial solution supplied to said material solution passage isdetermined, corresponding to that required for forming a film of 500 nmor less thickness on said substrate.

According to the process of producing a semiconductor of a twenty-fifthaspect of the invention, the quantity required for forming a film of 500nm or less thickness corresponds to that required for forming one atomiclayer or one molecular layer formed on said substrate.

According to the process of producing a semiconductor of a twenty-sixthaspect of the invention, in said quantitating step, a specific quantityof said material solution is stored in a storage section, correspondingto that required for forming one atomic layer or one molecular layer.

According to the process of producing a semiconductor of atwenty-seventh aspect of the invention, in said quantitating step, aspecific quantity of the material solution supplied from a materialsolution tank is stored in said storage section beforehand,corresponding to that required for forming one atomic layer or onemolecular layer so that it may be discharged to said evaporating sectionat a predetermined moment.

EFFECTS OF THE INVENTION

According to the first, tenth and nineteenth aspects of the presentinvention, it possible to improve the efficiency in the use of a rawmaterial gas noticeably, enabling uniform deposition according to theraw material gas used, diminishing maintenance frequency to improveproductivity. As compared with prior art.

According to the second, eleventh and twentieth aspects of the presentinvention, the supply of the material solution can be repeated multipletimes by the material solution discharging means, according to need.

According to the third, twelfth and twenty-first aspects of the presentinvention, the clogging with a solid matter can be prevented between theconnecting pipes and the carrier gas passage.

According to the fourth, thirteenth and twenty-second aspects of thepresent invention, the material solution is turned into the form of fineparticles or mists within the orifice pipe so as to be dispersed in thecarrier gas in order for all the material solutions to be easilyevaporated with heat, and thus all the material solution of thepredetermined quantity precisely determined by the material solutiondischarging means can be evaporated precisely, so that a constantquantity of raw material gases can always be supplied to the reactionchamber 402 even more accurately.

According to the fifth, fourteenth and twenty-third aspects of thepresent invention, quantity of the material solution can be determinedaccurately and easily.

According to the sixth, fifteenth and twenty fourth aspects of thepresent invention, only the material solution corresponding to thatrequired for forming a film of 500 nm thickness or less can be suppliedto the evaporation section.

According to the seventh, sixteenth and twenty-fifth aspects of thepresent invention, only the material solution corresponding to thatrequired for forming one atomic or molecular layer can be supplied tothe evaporation section.

According to the eighth, seventeenth and twenty-sixth aspects of thepresent invention, only the material solution corresponding to thatrequired for forming one atomic or molecular layer can be supplied tothe evaporation section, by simply storing the material solution in thestorage section.

According to the ninth, eighteenth and twenty-seventh aspects of thepresent invention, the material solution supplied from the materialsolution tank can be set apart by the storage section, accurate quantityof the material solution according to the film thickness of one atomiclayer or one molecular layer can be discharged to the evaporationsection at an optimal moment.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram showing an overall structure of a gasshower type heat CVD apparatus according to a first embodiment of theinvention;

FIG. 2 is a schematic diagram showing a detailed structure of avaporizer for CVD of the invention;

FIG. 3 is a schematic diagram showing an overall structure of the heatCVD apparatus according to a second embodiment of the invention;

FIG. 4 is a schematic diagram showing an overall structure of a plasmaCVD apparatus according to a third embodiment of the invention;

FIG. 5 is a schematic diagram showing an overall structure of a showertype plasma CVD apparatus according to a fourth embodiment of theinvention;

FIG. 6 is a schematic diagram showing an overall structure of a rollertype plasma CVD apparatus according to a fifth embodiment of theinvention;

FIG. 7 is a schematic diagram showing an overall structure of a rollertype plasma CVD apparatus according to a sixth embodiment of theinvention;

FIG. 8 is a schematic diagram showing an overall structure of a rollertype heat CVD apparatus according to a seventh embodiment of theinvention;

FIG. 9 is a schematic diagram showing an overall structure of aconventional ALD type CVD apparatus according to a prior art.

BEST MODE FOR CARRYING OUT THE INVENTION

Next is description of embodiments of the present invention withreference to the attached drawings.

(1) First Embodiment (1-1) Overall Structure of a Vertical Gas ShowerType Heat CVD Apparatus

In FIG. 1 where the same portions as those described in FIG. 9 aredenoted by the same reference numerals, reference numeral 1 shows a gasshower type heat CVD apparatus serving as a semiconductor productionapparatus as a whole, constituted such that a series of ALD operationsperformed by intermittently supplying a raw material gas from a upperportion of the reaction chamber 402 can be performed.

The gas shower type heat CVD apparatus 1 for manufacturingsemiconductors according to the present invention comprises a CVDsection 2 and a vaporizer 3 for CVD mounted in this CVD section 2, suchthat a carrier gas is always able to be supplied from the vaporizer 3for CVD to the reaction chamber 402 of the CVD section 2 at the time ofthe ALD operation.

The internal 415 of the reaction chamber 402 is kept at a predeterminedtemperature, using a heater (not shown) provided on the outside surfaceof the reaction-chamber body 413. Further, the reaction-chamber body 413has a door part 4 at a predetermined location, so that the substrate 420can be taken in and out from the internal 415 of the reaction chamberthrough this door part 4.

Further, an oxidization gas supply port 5 is provided in thereaction-chamber body 413 so that the oxidization gas (e.g., O₂) can besupplied through the oxidization gas supply port 5 to the internal 415of the reaction chamber. A shower plate 416 is provided in the upperportion of the reaction chamber interior 415, while a heater 422 for thesubstrate stage is provided in the substrate stage 421 and in the insideof the substrate stage 421.

The shower plate 416 diffuses the raw material gas supplied to theinterior space 417 through the gas ejecting hole 418 in a manner capableof spraying the raw material gas uniformly on the substrate 420 laid onthe substrate stage 421. In the meantime, reference numeral 8 designatesthe vaporizer which, in the case that a water vapor H₂O is required asan oxidization gas, for example, can evaporate H₂O and supply the sameinto the interior space 417 of the shower plate 416, using oxidizationgas O₂ as a carrier gas.

A shower plate heater 10 and a temperature sensor 11 are provided on theupper surface of the shower plate 416. Based on the temperature detectedby the temperature sensor 11, heating control of the shower plate heater10 is carried out through a control unit 12 so that the internal 415 ofthe reaction chamber and etc. can be heated to a predeterminedtemperature. In the meantime, a heater wiring 13 is connected to thisshower plate heater 10.

The heater 422 for use with the substrate stage is constituted such thatheating control thereof is carried out through the control unit 15,based on the temperature detected by the temperature sensor 14 so thatthe substrate stage 421 can be heated to a predetermined temperature.Incidentally, a heater wiring 16 is connected to this heater 422 for usewith the substrate stage. A pressure gauge 412 a for measuring thepressure in the interior 415 of the reaction chamber is provided in thereaction-chamber supporting part 412.

Moreover, the reaction-chamber supporting part 412 is communicated withthe exhaust tube 17 extending to an exhaust vacuum pump 410, and a trap18 is provided in the mid stream of this exhaust tube 17. Thus, thecarrier gas and the raw material gas supplied to the internal 415 of thereaction chamber from the vaporizer 3 for CVD are allowed to passthrough the exhaust tube 17 to be led to the trap 18, where specifictoxic substances in the exhaust gas are removed, and then dischargedfrom the vacuum pump 410 via the exhaust valve 409 and the like.

In addition to the foregoing structure, the reaction chamber 402 has thevaporizer 3 for CVD connected therewith at its gas introduction port 403through the reaction-chamber side valve 404. It is to be noted hereinthat the gas shower type heat CVD apparatus 1 of the present inventiondoes not perform the opening or closing operation of thereaction-chamber side valve 404 and the vent side valve 407 that hasheretofore been performed in the conventional CVD apparatus 400 (FIG. 9)at the time of the ALD operation for forming a thin film of one atomiclayer or one molecular layer one by one on the substrate 420, but allowsthe reaction-chamber side valve 404 to be always kept in an openedstate, and the vent side valve 407 to be always kept in a closed state.

Thus, the carrier gas can always be supplied to the reaction chamber 402from the vaporizer 3 for CVD at the time of the ALD operation. Inaddition, the carrier gas supplied to the reaction chamber 402 is alwaysdischargeable from the exhaust vacuum pump 410 through the exhaust tube17.

Moreover, the raw material gas obtained by evaporating only the materialsolution quantitated by the vaporizer 3 for CVD are capable of beingsupplied to the reaction chamber 402 at a predetermined moment.

Thus, inside the reaction chamber interior 415, a raw material gas issprayed uniformly on the substrate 420, a and heated by a heating meanssuch as a heater to thereby cause chemical reaction so that a thin filmof one atomic-layer or one molecular layer of a desired film thicknesscan be formed on the substrate 420.

That is, in the gas shower type heat CVD apparatus 1, when the supply ofthe raw material gas obtained by evaporating only the material solutionquantitated by the vaporizer 3 for CVD ceases, then only the carrier gasis supplied to the internal 415 of the reaction chamber again from thevaporizer 3 for CVD.

Thus, the thin film of one atomic layer or molecular layer of a desiredthickness can be formed on the substrate 420 even though thereaction-chamber side valve 404 remains in an opened state, and the ventside valve 407 in a closed state.

Thus, the gas shower type heat CVD apparatus 1 is allowed to evaporateonly the material solution of a predetermined quantity determinedaccording to the film thickness of one atomic layer or one molecularlayer formed on the substrate 420 as a thin-film formation subject, sothat this raw material gas is intermittently supplied to the internal415 of the reaction chamber.

Thus, it is possible to form a thin film of one atomic layer or onemolecular layer of a desired film thickness can be formed sequentiallyon the substrate 420, without performing the opening or closingoperation of the reaction-chamber side valve 404 and the vent side valve407 each time.

(1-2) The Detailed Structure of the Vaporizer for CVD

Next, the detailed structure of the vaporizer 3 for CVD is explainedbelow. This vaporizer 3 for CVD comprises an evaporation mechanism 20and a material-solution supply mechanism 21 provided in the evaporationmechanism 20. The evaporation mechanism 20 is connected with the gasintroduction port 403 of the reaction chamber through thereaction-chamber side valve 404.

In this case, the vaporizer 3 for CVD is constituted so that the carriergas may be always supplied to the reaction chamber 402 by theevaporation mechanism 20, while almost all the material solution of thepredetermined quantity supplied from the material-solution supplymechanism 21 may be reliably evaporated by the evaporation mechanism 20.

(1-2-1) The Structure of the Evaporation Mechanism

First, the evaporation mechanism 20 is explained hereinbelow. As shownin FIG. 2, in the evaporation mechanism 20, the carrier gas passage 22for supplying various carrier gases, such as nitrogen or argon gas, tothe internal 415 of the reaction chamber is constituted of a carrier gastube 23, the orifice tube 24 and the evaporating section 25.

In a preferred form of the invention, the evaporation mechanism 20 isconstituted such that a proximal end of the carrier gas tube 23 (namely,an inlet of the carrier gas passage 22) is connected with a supplymechanism (not shown) for supplying a carrier gas, while a distal end 30of the carrier gas tube 23 is connected with a proximal end 31 of theorifice tube 24, so that a high-speed carrier gas can be supplied to theorifice tube 24 from the carrier gas tube 23.

Incidentally, between the proximal end of the carrier gas tube 23 andthe supply mechanism are provided N₂ supplying valve and a mass flowcontroller (not shown). Moreover, a pressure transducer 32 is attachedto the carrier gas tube 23.

In the meantime, the pressure transducer 32 is always monitoring thepressure of the carrier gas in the carrier gas tube 23 and its change,through the accurate measurement and record thereof. The pressuretransducer 32 transmits to a control section (not shown) an outputsignal having a signal level according to the pressure level of thecarrier gas.

Thus way, the pressure measurement result of the carrier gas isdisplayed on a display (not shown) based on the output signal in orderfor an operator to be able to monitor the same. The operator can monitorthe clogging of the carrier gas passage 22 based on the measurementresult of the pressure.

The carrier gas tube 23 is designed so that an internal diameter thereofis greater than an internal diameter of the orifice tube 24, thusenabling the flow velocity of the carrier gas supplied to the orificetube 24 from the carrier gas tube 23 to be made even greater.

The orifice tube 24 is arranged vertically, including a convex portion34 of a trapezoidal cone shape at a distal end 33, said convex portion34 having an orifice 35 at an apex thereof. Thus, with the orifice tube24 having the convex portion 34 provided at the distal end, a slope 34 ais formed in a perimeter of an atomizing opening 36 at the tip end ofthe orifice 35, thus making it less likely for a residue to stay in theatomizing opening 36, enabling the inhibiting of clogging of theatomizing opening 36.

Incidentally, in the present embodiment, an apex angle, (theta) of theconvex portion 34 may preferably be an acute angle ranging from 45 to135 degrees, more preferably from 30 to 45 degrees, thus making itpossible to prevent the atomizing opening 36 from being clogged with thematerial compounds deposited.

The orifice 35 of the atomizing opening 36 is designed so as to have aninternal diameter smaller than that of the orifice tube 24 so that theflow velocity of the carrier gas supplied to the orifice 35 from theorifice pipe 24 may be even greater. The tip end of the orifice 35 isarranged here so that it may project in the interior space 38 of theevaporating section 25 due to the convex portion 34 of the orifice pipe24 being inserted into the proximal end 37 of the evaporating section25.

In addition to the foregoing structure, the orifice pipe 24 is in fluidcommunication with a plurality of connecting pipes 40 a-40 e (five, forexample in this case) from the proximal end 31 to the convex portion 34.A hereinafter-described material-solution supply mechanism 21 isprovided in each of these connecting pipes 40 a-40 e. Thus, the orificepipe 24 is constituted so that the material solution of a predeterminedquantity may be supplied from the material-solution supply mechanism 21through the connecting pipes 40 a-40 e.

In that case, the orifice pipe 24 is constituted such that the carriergas flowing at a high speed is sprayed against the material solutionsupplied, for example from the connecting pipe 40 a so that the materialsolution is turned into the form of fine particles or mists to therebybe dispersed into the carrier gas, and then atomized into theevaporating section 25 through the orifice 35 at high speed (230m/sec-350 m/sec).

In the case of the present embodiment, the orifice pipe 24 is designedto have an internal diameter of about, phi 1.0 mm, avertically-extending longitudinal length of about 100 mm, and theinternal diameter of the orifice 35 being set at about, phi 0.2-0.7 mm,so that the carrier gas can flow at a high speed thereinside.

The evaporating section 25 connected with the orifice pipe 24 is formedtubular and is arranged vertically like the orifice pipe 24. As shown inFIG. 2, the evaporating section 25 is formed so as to have an internaldiameter notably greater than the internal diameter of the orifice pipe24 so that the pressure in the evaporating section 25 may become smallerthan the pressure in the orifice pipe 24.

Thus, such a great difference in pressure is provided between theorifice pipes 24 and the evaporating section 25, whereby the materialsolution and the carrier gas are allowed to blow off from the distal end36 of the orifice pipe 24 at high speed (for example, 230 m/sec-350m/sec) so that they may be expanded within the interior space 38.

In the present embodiment, the pressure in the evaporating section 25 isset at about 10 Torr, while the pressure in the orifice pipe 24 at about500-1000 Torr, and thus a great difference in pressure is providedbetween the evaporating section 25 and the orifice pipe 24.

Incidentally, whilst the pressure of the carrier gas after a flow ratecontrol fluctuates with a carrier gas flow rate, a solution flow rateand the size of the orifice 35, it is desirable that the size of theatomizing opening 36 is finally chosen to control the pressure of thecarrier gas so as to set the same to 500-1000 Torr.

In addition, in the perimeter of the evaporating section 25, there isprovided a heater 42 as a heating means between the proximal end 37 andthe distal end 41 (namely, the outlet of the carrier gas passage 22), asshown in FIG. 1 so that the evaporating section 25 may be heated toabout 270 degrees C. by this heater 42. In the present embodiment, theproximal end 37 of the evaporating section 25 is formed into asubstantially hemisphere shape, and thus the proximal end 37 side can beheated evenly by the heater 42.

In this way, the evaporating sections 25 is constituted such that thematerial solution dispersed and turned into misty form by the high-speedcarrier gas flow within the orifice pipe 24 may be instantly heated andmomentarily evaporated by the heater 42. As that moment, it is desirablethat a period from the time the material solution was mixed within theorifice pipe 24 until it is atomized into the evaporating section 25 beextremely short (preferably less than 0.1 to 0.002 second). Owing tosuch a high-speed carrier gas flow, the material solution is turned intofine particulars or misty form, immediately after being dispersed withinthe orifice pipe 24, and is evaporated within the evaporating section 25instantaneously. Moreover, such a phenomenon that only a solventevaporates is inhibited.

It is to be noted herein that by atomizing the material solution and thecarrier gas into the evaporating section 25 at high speed, a mist sizecan be further miniaturized (a mist diameter being one micrometer orless), thus enabling an increase of an evaporation area as well as anincrease of an evaporation rate. In the meantime, one-digit decrease ofa mist size will result in one-digit increase of an evaporation area.

It is preferable to design the angle of the atomizing opening 36 and thesize of the evaporating section 25 so that the mist ejected from theatomizing opening 36 may not collide with the inner wall of theevaporating section 25. It is because if the mist collides with theinner wall of the evaporating section 25, it will adhere to the wallsurface, and thus the evaporation area will decrease extraordinarily andthe evaporation rate will fall. Also, it is because the mist adhered tothe wall of the adhered to the evaporating-section 25 wall for a longtime is sometimes thermally decomposed and changes into a non-evaporablecompound.

Moreover, the evaporating section 25 is decompressed thereinside, andthus sublimation temperature of the material compounds contained in eachmaterial solution can be lowered. As a result, the material solution canbe evaporated easily with the heat from the heater 42.

Thus, the evaporating section 25 evaporates the material solution,supplies it as a raw material gas to the reaction chamber 402, where athin film of one atomic layer or one molecular layer is formed in thisreaction chamber 402 through CVD method.

In the meantime, the proximal end 37 of the evaporating section 25 hasan adiabator 43 between the orifice pipes 24 and itself so that the heatfrom the evaporating section 25 may be less likely to be transmitted tothe orifice pipe 24 with this adiabator 43. Incidentally the hermeticseal of the proximal end 37 of the evaporating section 25 is carried outby an O-ring 44. Moreover, another adiabator 46 is provided in acoupling member 45 which couples the orifice pipe 24 with theevaporating section 25.

It is desirable that the mist sprayed from the orifice 35 does not wetthe inner wall of the evaporating section 25. This is because anevaporation area decreases extraordinarily if the inner wall is wet, ascompared with just being misty. In other words, it is desirable toemploy such a construction that the inner wall of the evaporatingsection 25 does not become tainted at all. Moreover, it is desirable toform the inner wall of the evaporating section 25 in mirror finish sothat the dirt or taint on the inner wall of the evaporating section 25can be evaluated easily.

According to the evaporation mechanism 20, the material solution isatomized instantaneously by a high-speed carrier gas flow so that it canbe easily evaporated by the heat of the heater 42. As a result, even ifthe material solution is the one obtained by dissolving a hardlyevaporable material compound in solvent, yet it is able to be evaporatedin the evaporating section 25 easily.

For example, in the case that a SBT (tantalic acid strontium bismuth)film is formed on the substrate 420, it is possible to useSr[Ta(OEt)5(OEtOMe)]2, Bi(OtAm)3 as material compounds, and it ispreferable to use toluene as a solvent. Moreover, when forming a PZT(titanic acid lead zirconate) film on the substrate 420, it is possibleto use as materials compounds Pb(DPM)2, Zr(DIBM)4, Ti(Oi-Pr)2(DPM)2 orPb(METHD)2, Zr(MMP)4, and Ti(MMP)4, and it is preferable to use tolueneas a solvent.

Moreover, according to the evaporation mechanism 20, the carrier gaspressurized in the carrier gas tube 23 so as to flow at a high speed isintroduced into the orifice pipe 24 (for example, carrier gas being500-1000 Torr, 200 ml/min-2 L/min), the temperature rise in the materialsolution can be inhibited in the orifice pipe 24.

According to the evaporation mechanism 20, therefore, evaporation of thesolvent only in the material solution in the orifice pipe 24 can beinhibited, and thus it is possible to prevent the concentration of thematerial solution from becoming too high in the orifice pipe 24, thusenabling the inhibition of viscosity rise and the deposition of thematerial compound.

Furthermore, according to the evaporation mechanism 20, the materialsolution dispersed in the carrier gas can be evaporated by theevaporating section 25 instantaneously, and thus it is possible toprevent only the solvent in the material solution from being evaporatedin the orifice 35 or in the vicinity thereof, and thus the clogging ofthe orifice 35 can be deterred. Thus way, continuous duty time of thevaporizer 3 for CVD can be lengthened.

(1-2-2) Structure of the Material-Solution Supply Mechanism

Next, the material-solution supply mechanism 21 provided in theforegoing evaporation mechanism 20 is explained below. Although thematerial-solution supply mechanism 21 for determining the quantity ofthe material solution, is provided in each of the connecting pipes 40a-40 e, the respective material-solution supply mechanisms 21 onlydiffer in the kind of the material solution supplied to the orifice pipe24, and all of them have the same structure. For the sake of simplicity,only the material-solution supply mechanism 21 provided in theconnecting pipe 40 a is explained hereinbelow.

The connecting pipes 40 a-40 e are arranged at the orifice pipe 24 sothat the respective openings may not face each other, whereby, forexample, the material solution supplied to the orifice pipe 24 from theopening of the connecting pipe 40 a is reliably prevented from flowinginto the openings of other connecting pipes 40 b-40 e.

In that case, as shown in FIG. 1, the material-solution supply mechanism21 is constituted such that the material solution stored in a materialsolution storage tank 50 may be supplied to the orifice pipe 24 byallowing it pass through the predetermined material solution passage 51via the liquid mass flow controller (LMFC) 52, a block valve 53, and themicro-metering pump 54 in sequence. This liquid mass flow controller 52serves to control the flow rate of the material solution flowing throughthe material solution passage 51.

As shown in FIG. 2, the block valve 53 comprises first to fourthswitching valves 55 a-55 d, controlled by a control section which is notshown herein.

In practice, when supplying a material solution to the orifice pipe 24,the block valve 53 is capable of supplying the material solution to themicro-metering pump 54 by switching only the first switching valve 55 ainto an opened state while the other switching valves 55 b-55 d into aclosed state.

The micro-metering pump 54 is controlled by the control section togetherwith the block valve 53 so that the material solution of predeterminedquantity according to the film thickness of one atomic layer or onemolecular layer formed on the substrate 420 can be stored in the storagesection 56, and it is capable of determining quantity of the materialsolution supplied from the material solution tank 50.

Thus, the micro-metering pump 54 serving as a material solutiondischarging means is capable of storing the material solution suppliedfrom the material solution tank 50 once in the storage section 56,according to the film thickness of one atomic layer or one molecularlayer formed on the substrate 420 so that it may be set apart from thematerial solution supplied from the material solution tank 50.

The capacity of the storage section 56 is preset so that the materialsolution of a predetermined quantity most suitable for forming oneatomic layer or one molecular layer may be stored therein, whereby thematerial solution of an optimal predetermined quantity for forming thefilm thickness of one atomic or molecular layer can be quantitatedeasily and reliably, by simply storing the material solution in thestorage section 56.

Once the micro-metering pump 54 stores the material solution of suchpredetermined quantity in the storage section 56, then it will wait fora control signal from the control section. Then, if a predeterminedcontrol signal is received from the control section, the micro-meteringpump 54 is then capable of supplying the material solution of thepredetermined quantity stored in the storage section 56 to the orificepipe 24 at a predetermined moment.

Accordingly, the orifice pipe is allowed to have such determinedquantity of the material solution supplied to the carrier gas flowing athigh speed, which in turn changes the material solution into the form offine particles or mists, so as to be supplied to the evaporating section25 with such misty material solution dispersed in the carrier gas.

In addition to the foregoing structure, the material-solution supplymechanism 21 is constituted, as shown in FIG. 1, such that when thematerial solution is not being supplied to the orifice pipe 24 from themicro-metering pump 54, the solvent stored in a solvent tank 57 may besupplied to the orifice pipe 24 by allowing it to pass through apredetermined solvent passage 58 via the liquid mass flow controller(LMFC) 59, the cut valve 60, and the connecting pipe 40 a in sequence.

In that case, the control section switches the second switching valve 55b and the third switching valve 55 c into a closed state, while the cutvalve 60 into an opened state, whereby the connecting pipe 40 a isopened so as to be able to supply the solvent to the orifice pipe 24.Thus, it is possible to prevent the connecting pipe 40 a from beingclogged with a solid matter by allowing the solvent only to flow intothe orifice pipe 24 from the connecting pipe 40 a.

On the other hand, the control section switches the second switchingvalve 55 b and the cut valve 60 into a closed state, while the thirdswitching valve 55 c into an opened state, thereby allowing the solventto flow into a vent tube 61 via the block valve 53 to be exhausted.

Furthermore, in the case that the control section switches the firstswitching valve 55 a into a closed state so that the material solutionis not being supplied to the micro-metering pump 54, the control sectionswitches the third switching valve 55 b and the cut valve into a closedstate, while the second switching valve 55 b into an opened state,whereby the solvent can be supplied to the orifice pipe 24 via the blockvalve 53, micro-metering pump 54 and the connecting pipe 40 a insequence. Thus, it is possible to prevent the micro-metering pump 54from being clogged with a solid matter by allowing the solvent only toflow into the micro-metering pump 54.

In the meantime, the control section switches the first switching valve55 a, the second switching valve 55 b and the third switching valve 55 cinto a closed state, while the fourth switching valve 55 d into anopened state, thereby allowing the material solution to flow into a venttube 61 via the block valve 53 to be exhausted.

(1-3) Operation and Effect

According to the foregoing structure, the vaporizer 3 for CVD of theinvention is provided with the micro-metering pump 54 in the materialsolution passage 51 between the material solution tank 50 and theorifice pipe 24, determining the quantity of the material solutionsupplied from the material solution tank 50, using the micro-meteringpump 54 to thereby store the material solution in the storage section 56as much as required for forming the film thickness of one atomic layeror one molecular layer.

Subsequently, in the vaporizer 3 for CVD, the material solution of thepredetermined quantity quantitated by the micro-metering pump 54 issupplied to the carrier gas flow that is always flowing towards thereaction chamber 402 at high speed in the orifice pipe 24.

Thus, the material solution of the predetermined quantity is turned intothe form of fine particles or mists and dispersed in the carrier gas,and then the dispersed material solution is evaporated in theevaporation section 25 as it is to thereby be supplied to the reactionchamber 402 as a raw material gas.

According to the gas shower type heat CVD apparatus 1 performing a CVDprocess in this way, it is possible to supply, as a raw material gas,only the material solution of the predetermined quantity determined bythe micro-metering pump 54 to the reaction chamber 402, thereby sprayingthe thus obtained raw material gas uniformly on the substrate 420, whichis then heated by the heater 422 or the like, to thereby cause achemical reaction on the substrate 420.

In the gas shower type heat CVD apparatus 1, if the material solution ofthe predetermined quantity determined by the micro-metering pump 54 isall supplied to the evaporation mechanism 20, then the supply of a rawmaterial gas to the internal 415 of the reaction chamber is allowed tostop. As a result, only the carrier gas is supplied to the reactionchamber 402 again. Consequently, according to the gas shower type heatCVD apparatus 1 of the invention, the thin film of one atomic-layer orone molecular layer of a desired film thickness can be formed on thesubstrate 420, without performing the opening or closing operation ofthe reaction-chamber side valve 404 and the vent side valve 407.

Moreover, according to the gas shower type heat CVD apparatus 1, when itfinishes carrying out the deposition operation for forming the thin filmof one atomic layer or one molecular layer, the material solution of thepredetermined quantity determined by the micro-metering pump 54 issupplied again to the evaporation mechanism 20 after a predeterminedtime, so that another thin film of one atomic layer or one molecularlayer of a desired film thickness is formed on the substrate 420.

Thus, according to the gas shower type heat CVD apparatus 1 of theinvention, such a deposition operation that only the predeterminedquantity of the material solution determined by the micro-metering pump54 is supplied to the evaporation mechanism 20 is repeated multipletimes so that a raw material gas is supplied to the reaction chamber 402intermittently, thus enabling the deposition of a predeterminedthickness one by one. Consequently, a high-density and high-quality thinfilm can be formed on the substrate 420 in this way.

Thus, the gas shower type heat CVD apparatus 1 of the invention does notneed to perform any opening or closing operation of the reaction-chamberside valve 404 and the vent side valve 407 that have been performed inconventional CVD apparatus 400 (FIG. 9) at the time of the ALD thatrepeats deposition operation, but evaporates only the material solutionof the predetermined quantity precisely determined by the micro-meteringpump 54 in the evaporation mechanism 20, and supplies the same as a rawmaterial gas to the reaction chamber 402, thereby enabling forming afilm of a desirable film thickness made of one atomic layer or onemolecular layer within the reaction chamber 402.

Accordingly, the gas shower type heat CVD apparatus 1 of the inventionenables a thin film of a desired thickness made of one atomic layer orone molecular layer to be formed on the substrate 420 one by one, whileavoiding a raw material gas being thrown away by the opening or closingoperation of the reaction-chamber side valve 404 and the vent side valve407.

Moreover, the gas shower type heat CVD apparatus 1 of the inventionallows the reaction-chamber side valve 404 to be always in an openedstate while allowing the vent side valve 407 to be always in a closedstate at the time of ALD operation so that the carrier gas from thevaporizer 3 for CVD may always be supplied to the reaction chamber 402,whereby pressure change in the reaction chamber 402 does not occur andthus the deposition process condition inside the reaction chamber 402can be kept uniformly.

Furthermore, the gas shower type heat CVD apparatus 1 eliminates theneed for frequent repetitions of the opening or closing operation of thereaction-chamber side valve 404 and the vent side valve 407 at the timeof ALD operation, and thus it is possible to extend the operating livesof these reaction-chambers side valve 404 and the vent side valve 407.As a result, frequency of maintenance can be diminished to thereby avoidoperating rates' falls as compared with the conventional ones.

Also, according to the gas shower type heat CVD apparatus 1 of theinvention, the storage section 56 of the micro-metering pump 54 ispreset so that the material solution of the optimal predeterminedquantity for forming the film thickness of one atomic layer or onemolecular layer may be stored, and thus the material solution of theoptimal predetermined quantity for forming the film thickness of an oneatomic layer or one molecular layer can be supplied to the evaporationmechanism 20 easily and reliably by simply storing the material solutionin the storage section 56.

Moreover, the evaporation mechanism 20 used in the vaporizer 3 for CVDallows the material solution to be turned into the form of fineparticles or mists within the orifice pipe 24 so as to be dispersed inthe carrier gas in order for all the material solutions to be easilyevaporated with heat, while controlling the temperature rise of thematerial solution in the orifice pipe 24, preventing the deposition ofthe material compounds, whereby all the material solution of thepredetermined quantity precisely determined by the micro-metering pumpcan be evaporated precisely, so that an accurately constant quantity ofraw material gases can always be supplied to the reaction chamber 402 inthis way.

According to the above structure, the carrier gas continues to besupplied to the reaction chamber 402 at the time of ALD operation, whilethe material solution of predetermined quantity according to the filmthickness of one atomic or molecular layer quantitated by themicro-metering pump 54 is intermittently supplied to the evaporationmechanism 20, and the raw material gas composed of the material solutionof the predetermined quantity thus obtained is supplied to the reactionchamber 402 together with the carrier gas.

Accordingly, the gas shower type heat CVD apparatus 1 of the inventionenables a thin film of a desired thickness made of one atomic layer orone molecular layer to be formed on the substrate 420 one by one, whileavoiding a raw material gas being thrown away by the opening or closingoperation of the reaction-chamber side valve 404 and the vent side valve407. Thus way, the efficiency in the use of a raw material gas can beimproved remarkably, according to the quantity of the raw material gasthat is not thrown away in the process of forming a thin film of oneatomic or molecular layer one by one.

Moreover, the gas shower type heat CVD apparatus 1 of the inventionallows the reaction-chamber side valve 404 to be always in an openedstate at the time of ALD operation so that the carrier gas from thevaporizer 3 for CVD may always be supplied to the reaction chamber 402,so that pressure change in the reaction chamber 402 does not occur andthus the deposition process condition inside the reaction chamber 402can be kept uniform, thus enabling the film having a film thickness ofone atomic or molecular layer according to the supplied raw material gasto be uniformly formed on the substrate 420.

Furthermore, the gas shower type heat CVD apparatus 1 eliminates theneed for frequent repetitions of the opening or closing operation of thereaction-chamber side valve 404 and the vent side valve 407 at the timeof ALD operation, and thus it is possible to extend the operating livesof these reaction-chamber side valve 404 and the vent side valve 407. Asa result, frequency of maintenance can be diminished to thereby improveproductivity.

(2) Second Embodiment

In FIG. 3 where the same portions as those illustrated in FIG. 1 aredesignated by the same reference numerals, numeral 70 shows a heat CVDapparatus as a semiconductor production apparatus, which has the samestructure as the foregoing first embodiment, except that it isconstituted so as to be able to perform a series of ALD operationsaccompanied with the intermittent supply of the raw material gas fromthe side of the reaction chamber 71. Since the heat CVD apparatus 70performing such a CVD process is also equipped with the vaporizer 3 forCVD, the same effect as mentioned above can be obtained.

(3) Third Embodiment

In FIG. 4 where the same portions as those illustrated in FIG. 1 aredesignated by the same reference numerals, numeral 75 shows a plasma-CVDapparatus as a semiconductor production apparatus, which differs fromthe foregoing first embodiment in the structure of the CVD section 76.

In the present embodiment, an RF (Radio Frequency) plasma generatorelectrode 77 is provided in the reaction chamber 402, so that plasma canbe generated within the reaction chamber 402 by the RF plasma generatorelectrode 77. In the meantime, numeral 79 denotes a noise cutoff filter.

In that case, an RF power supply 78 is arranged above the reactionchamber 402, and the RF power supply 78 is equipped with the plasmagenerator electrode 77. Thus, the plasma-CVD apparatus 75 allows plasmato be generated in the reaction chamber to cause a chemical reaction onthe substrate 420 so that the thin film of one atomic layer or onemolecular layer of a desired film thickness. Since the plasma CVDapparatus 75 performing such a CVD process is also equipped with thevaporizer 3 for CVD, the same effect as the foregoing first embodimentcan be obtained.

(4) Fourth Embodiment

In FIG. 5 where the same portions as those illustrated in FIG. 1 aredesignated by the same reference numerals, numeral 80 shows a showertype plasma-CVD apparatus as a semiconductor production apparatus, whichdiffers from the first embodiment in the structure of the CVD section81, comprising a plasma system and a shower plate 416.

In the present embodiment, the CVD section 81 is formed with an RF(Radio Frequency) power supply 83 via an insulating material 82 abovethe shower plate 416, and the shower plate heater 10 is providedthereabove. In addition, numeral 84 denotes a noise cutoff filter forpreventing RF voltage from entering into the control unit 12. Since theshower type plasma-CVD apparatus 80 performing such a CVD process isalso equipped with the vaporizer 3 for CVD, the same effect as theforegoing first embodiment can be obtained.

(5) Fifth Embodiment

In FIG. 6, numeral 90 shows a roller type plasma-CVD apparatus as asemiconductor production apparatus, comprising two or more vaporizers 3for CVD in a roller type CVD section 91.

In the roller type plasma-CVD 90, a plurality of plasma generators 92a-92 e are provided in the roller type CVD section 91, in which a tape93 for forming a film thereon is allowed to travel in a forwarddirection F, or otherwise, in a reverse direction R, whereby a thin filmis formed in each of the plasma generators 92 a-92 e so thatmulti-layered films made from different materials can be formed.

In practice, according to this roller type plasma-CVD apparatus 90, thevaporizer 3 for CVD of the present invention is provided in each of theplasma generators 92 a-92 e, and thus the same effect as the foregoingfirst embodiment can be obtained.

Incidentally, in this roller type plasma-CVD apparatus 90, a firstrolling-up roller 96 and a second rolling-up roller 97 are arranged onboth sides of the deposition roller 95 in the reaction chamber 94.Moreover, a first feed roller 98 and a first tension control roller 99are arranged at one side of the deposition roller 95, while a secondfeed roller 100 and a second tension control roller 101 are arranged atthe other side of the deposition roller 95. In the meantime, thediameter of the deposition roller 95 is as large as 1,000-20,000 mm, anda width thereof is 2 m, for example.

Accordingly, in the roller type plasma-CVD apparatus 90, a travelingpath for the tape 93 to travel thereon is provided from the firstwind-up roller 96 through the first feed roller 98, the first tensioncontrol roller 99, the deposition roller 95, the second tension controlroller 101, the second feed roller 100 up to the second wind-up roller97, whereby the tape 93 for forming a film thereon can travel along thetraveling path in the direction from the first rolling-up roller 96 tothe second rolling-up roller 97 (forward direction F), as well as in thedirection from the second rolling-up roller 97 to the first rolling-uproller 96 (reverse direction R).

In that case, the plasma generators 92 a-92 e are each provided inresponse to respective areas on the deposition roller 95, so that thevaporizer 3 for CVD is allowed to act upon respective portions of thetape 93 located on the areas to thereby form a thin film. Moreover, eachof the plasma generators 92 a-92 e and the vaporizer 3 for CVD arecontrolled to be able to set various CVD and/or film conditionsindividually, enabling any of them to perform or stop deposition processindividually.

In the meantime, a partition plate 105 is arranged between the adjacentones of the plasma generators 92 a-92 e, in order to prevent aninterference of a raw material gas. Incidentally, numeral 106 designatesan exhaust tube, 107 an anti-adhesive plate, 108 a gas shower electrodeand 109 an RF power supply, respectively. In the present embodiment, thedeposition roller 95 is grounded, and the gas shower electrode 108 isconnected to the terminal of the RF power supply 109, and thus theelectric potential of the plasma generators 92 a-92 e is higher.

According to the roller type plasma-CVD apparatus 90 which performs sucha CVD deposition process, the tape 93 for forming a film thereon isallowed to travel in the forward direction F or in the reverse directionR, which is repeated alternately so that a multilayer film of 50layers-1000 layers, for example, can be formed in a comparativelyefficient manner.

(6) Sixth Embodiment

In FIG. 7 where the same portions as those illustrated in FIG. 6 aredesignated by the same reference numerals, numeral 120 shows a rollertype plasma-CVD apparatus as a semiconductor production apparatus, whichdiffers from the foregoing fifth embodiment in that the electricpotential of the deposition roller 95 is higher. Namely, the roller typeplasma-CVD apparatus 120 differs in that one terminal of one RF powersupply 121 is connected to the deposition roller 95, while the gasshower electrode 108 of each of the plasma generators 92 a-92 e isgrounded. Since such roller type plasma-CVD apparatus 120 also comprisesthe vaporizer 3 for CVD of the present invention, the same effect as thefirst embodiment can be obtained.

(7) Seventh Embodiment

In FIG. 8 where the same portions as those illustrated in FIG. 6 aredesignated by the same reference numerals, numeral 130 shows a rollertype heat CVD apparatus as a semiconductor production apparatus. Theroller type heat CVD apparatus 130 differs from the foregoing fifthembodiment in that it is not provided with a plasma generator and novoltage is applied between the shower plate sections 131 a-131 e and thedeposition roller 95. This roller type heat CVD apparatus 130 isconstituted so that the tape 93 for forming a film thereon can be heatedmainly by the deposition roller 95.

Since such roller type heat-CVD apparatus 130 also comprises thevaporizer 3 for CVD of the present invention provided in each of theshower plate sections 131 a-131 e, the same effect as the firstembodiment can be obtained.

(8) Other Embodiments

In the meantime, the present invention is not limited to the foregoingembodiments, and various modifications are possible. Although only onekind of the material solution is supplied to the evaporation mechanism20 from the micro-metering pump 54 provided in the connecting pipe 40 ain the foregoing embodiments, the present invention should not belimited thereto, but the material solutions of different kinds from eachmicro-metering pump 54 provided in the connecting pipes 40 a-40 e may besupplied to the evaporation mechanism 20 either at the same time orsequentially at intervals.

Moreover, although the foregoing embodiments employ the evaporationmechanism 20 constituted so that a material solution is atomized andchanged into misty form instantaneously by the high-speed carrier gasflow so that it may be easily evaporated with the heat of the heater 42,the present invention should not be limited thereto, but an ordinaryevaporation mechanism usually used for CVD may be employed.

In the case that such ordinary evaporation mechanism is employed, theevaporation section may not be provided in the vicinity of the gasintroduction port 403 (FIG. 1) of the reaction chamber 402, but in theconnecting pipes 40 a-40 e formed in a bifurcation of the conventionalgas supply passage 405 as shown in FIG. 9 so that the raw material gasobtained in the evaporation section may be supplied to the gas supplypassage 405 (FIG. 9) through the connecting pipes 40 a-40 e.

In other words, the object of the invention is achieved if theevaporation section is provided in a predetermined location between theoutlet of the carrier gas passage 22 and the micro-metering pumps 54 sothat when supplying a material solution to the evaporation section fromthe material solution tank 50, the material solution of predeterminedquantity according to the film thickness of one atomic or molecularlayer determined by the micro-metering pump 54 may be supplied to theevaporation mechanism 20, and only the raw material gas composed of theresultant material solution of the predetermined quantity may besupplied to the reaction chamber 402.

Furthermore, although the material solution determined by themicro-metering pump 54 is intermittently supplied to the evaporationmechanism 20 at regular intervals in the foregoing embodiments, thepresent invention should not be limited thereto, but the materialsolution determined by the micro-metering pump 54 may be intermittentlysupplied to the evaporation mechanism 20 at irregular intervals. In thatcase, the supply of the material solution may be performed plural timesby the micro-metering pump 54, where necessary.

Still further, in the foregoing embodiments is proposed the use of anapparatus for CVD process, such as the heat CVD apparatus 70, theplasma-CVD apparatus 75, the shower type plasma-CVD apparatus 80, theroller type plasma-CVD apparatus 90, the roller type plasma-CVDapparatus 120, the roller type heat CVD-apparatus 130, etc. but thepresent invention should not be limited thereto but may be applicable toother various semiconductor production apparatus that perform variousother processes such as an etching apparatus for performing etchingprocess in the reaction chamber, a sputtering apparatus which performs asputtering process in the reaction chamber, or an ashing process thatperform ashing process in the reaction chamber, etc. Since the vaporizerof the present invention can be provided in the reaction chamber inthese cases as well, the same effect as the above-mentioned embodimentscan be obtained.

Furthermore, although in the foregoing embodiments is proposed the useof the deposition method performed in the deposition apparatus, as asemiconductor manufacturing method, the invention should not be limitedthereto, but may be applied to other semiconductor manufacturing methodssuch as etching method.

Furthermore, although in the foregoing embodiments is proposed the useof the metering pump 54 to determine the material solution according tothe quantity of one atomic or molecular layer, but the present inventionshould not be limited thereto. For example, the metering pump 54 maydetermine other various specific quantities such as the quantityaccording to a film thickness of 500 nm or less, In that case, it ispossible to supply the material solution to the evaporation section 25by the quantity according to a film thickness of 500 nm or less.

Moreover, although in the foregoing embodiments is proposed the use ofthe micro-metering pump 54 with a predetermined storage capacity of thematerial solution, the present invention should not be limited thereto.For example, a micro-metering pump whose storage capacity is variabledepending on cases may be used.

Furthermore, although in the foregoing embodiments is proposed the useof the micro-metering pumps 54 as a material-solution discharge means,the present invention should not be limited thereto. As long as it ispossible to determine a preset quantity of the material solution so asto be able to supply the same to the evaporation mechanism 20, othervarious material-solution discharge means may be used.

Furthermore, although in the foregoing embodiments is proposed the useof the solid material compound dissolved in solvent as the materialsolution, the present invention should not be limited thereto. Forexample, liquid material compound itself may be used as the materialsolution

1. A vaporizer for supplying a raw material gas to a reaction chamber, said material gas being obtained by evaporating a material solution, comprising: a carrier gas passage for allowing the carrier gas to flow from an inlet toward an outlet; a material solution passage to which said material solution is supplied; a connecting pipe for communicating said carrier gas passage with said material solution passage; a material solution discharging device determining quantity of said material solution supplied to said material passage to discharge the same to said connecting pipe; an evaporating section provided between the outlet of said carrier gas passage and said material solution discharging device, said evaporating section evaporating a predetermined quantity of said material solution discharged from said material solution discharging device.
 2. The vaporizer according to claim 1, wherein said material solution discharging device discharges said material solution intermittently to said connecting pipe.
 3. The vaporizer according to claim 1, further comprising a solvent passage for supplying a purge solvent to said carrier gas passage.
 4. The vaporizer according to claim 1, wherein said carrier gas passage comprises: a carrier gas tube to which said carrier gas is supplied; an orifice pipe having said carrier gas supplied from said carrier gas tube, said orifice pipe turning said material solution into the form of fine particles or mists to be supplied to said evaporating section with said material solution being dispersed into the carrier gas, and wherein said evaporating section comprises a heating means for heating and evaporating said material solution dispersed in said carrier gas.
 5. The vaporizer according to claim 1, wherein said material solution discharging device comprises a micro-metering pump.
 6. The vaporizer according to claim 1, wherein said material solution discharging device determines quantity of said material solution supplied to said material solution passage so that the determined quantity thereof corresponds to that required for a film thickness of 500 nm or less to be formed on a substrate.
 7. The vaporizer according to claim 6, wherein said determined quantity of the material solution corresponds to that required for forming one atomic layer or one molecular layer formed on said substrate.
 8. The vaporizer according to claim 7, wherein said material solution discharging device comprises a storage section for storing a specific quantity of said material solution, corresponding to that required for forming one atomic layer or one molecular layer.
 9. The vaporizer according to claim 8, wherein said material solution discharging device stores said specific quantity of the material solution supplied from a material solution tank in said storage section beforehand so that it may be discharged to said evaporating section at a predetermined moment.
 10. A semiconductor production apparatus including a reaction chamber for placing a substrate thereon and a vaporizer for supplying a raw material gas to the reaction chamber, said material gas being obtained by evaporating a material solution, wherein said vaporizer comprises: a carrier gas passage for allowing the carrier gas to flow from an inlet toward an outlet; a material solution passage to which said material solution is supplied; a connecting pipe for communicating said carrier gas passage with said material solution passage; a material solution discharging device determining quantity of said material solution supplied to said material passage to discharge the same to said connecting pipe; an evaporating section provided between the outlet of said carrier gas passage and said material solution discharging device, said evaporating section evaporating a predetermined quantity of said material solution discharged from said material solution discharging device.
 11. The semiconductor production apparatus according to claim 10, wherein said material solution discharging device discharges said material solution intermittently to said connecting pipe.
 12. The semiconductor production apparatus according to claim 10, further comprising a solvent passage for supplying a purge solvent to said carrier gas passage.
 13. The semiconductor production apparatus according to claim 10, wherein said carrier gas passage comprises: a carrier gas tube to which said carrier gas is supplied; an orifice pipe having said carrier gas supplied from said carrier gas tube, said orifice pipe turning said material solution into the form of fine particles or mists to be supplied to said evaporating section with said material solution being dispersed into the carrier gas, and wherein said evaporating section comprises a heater heating and evaporating said material solution dispersed in said carrier gas.
 14. The semiconductor production apparatus according to claim 10, wherein said material solution discharging device comprises a micro-metering pump.
 15. The semiconductor production apparatus according to claim 10, wherein said material solution discharging device determines quantity of said material solution supplied to said material solution passage so that the determined quantity thereof corresponds to that required for a film thickness of 500 nm or less to be formed on a substrate.
 16. The semiconductor production apparatus according to claim 15, wherein said determined quantity of the material solution corresponds to that required for forming one atomic layer or one molecular layer formed on said substrate.
 17. The semiconductor production apparatus according to claims 16, wherein said material solution discharging device comprises a storage section for storing a specific quantity of said material solution, corresponding to that required for forming one atomic layer or one molecular layer.
 18. The semiconductor production apparatus according to claim 17, wherein said material solution discharging device stores said specific quantity of the material solution supplied from a material solution tank in said storage section beforehand so that it may be discharged to said evaporating section at a predetermined moment.
 19. A process of producing a semiconductor in which a raw material gas obtained by evaporating a material solution is supplied into a reaction chamber where a substrate is surface treated, said method comprising: a carrier gas supply step for supplying the carrier gas to said reaction chamber by allowing the carrier gas to flow from an inlet toward an outlet of a carrier gas passage; a material-solution supply step for supplying said material solution to said material solution passage; a quantitating step for determining quantity of said material solution supplied to said material solution passage; a material solution discharging step for discharging a predetermined quantity of said material solution quantitated in the quantitating step to said connecting pipe communicating said carrier gas passage with said material solution passage; and an evaporating step for evaporating said predetermined quantity of said material solution discharged in said material solution discharging step, using an evaporating section provided between the outlet of said carrier gas passage and a means for discharging said material solution.
 20. The process of producing a semiconductor according to claim 19, wherein said material solution is discharged intermittently to said connecting pipe in said material solution discharging step.
 21. The process of producing a semiconductor according to claim 19, comprising a purge solvent supply step for supplying a purge solvent to said evaporating section from said carrier gas passage through said connecting pipe, instead of said material solution discharging step and said evaporating step.
 22. The process of producing a semiconductor according to claim 19, wherein said carrier gas supply step includes a sub-step for supplying said carrier gas to said orifice pipe from said carrier gas tube; and after the sub-step, said material solution is discharged to said orifice pipe in said material solution discharging step, so that said material solution turned into the form of fine particles or mists in said orifice pipe to be supplied to said evaporating section with said material solution being dispersed into the carrier gas, and then said material solution dispersed in said carrier gas through said evaporating step is heated by a heater provided in said evaporating section.
 23. The process of producing a semiconductor according to claim 19, wherein quantity of said material solution is determined by a micro-metering pump in said quantitating step.
 24. The process of producing a semiconductor according to claim 19, wherein in said quantitating step, quantity of said material solution supplied to said material solution passage is determined, corresponding to that required for forming a film of 500 nm or less thickness on said substrate.
 25. The process of producing a semiconductor according to claim 24, wherein the quantity required for forming a film of 500 nm or less thickness corresponds to that required for forming one atomic layer or one molecular layer formed on said substrate.
 26. The process of producing a semiconductor according to claim 25, wherein in said quantitating step, a specific quantity of said material solution is stored in a storage section, corresponding to that required for forming one atomic layer or one molecular layer.
 27. The process of producing a semiconductor according to claim 26, wherein in said quantitating step, a specific quantity of the material solution supplied from a material solution tank is stored in said storage section beforehand, corresponding to that required for forming one atomic layer or one molecular layer so that it may be discharged to said evaporating section at a predetermined moment. 